Is it time for open processors? • Hacker News Board

Re: Is it time for open processors?

#201

Post by wavegeek » Sat, Jan 20, 2018, 3:41 AM UTC

pjc50 wrote: post #143

lambda wrote: post #106

Earlier quoted context omitted.

Why give up on performance? IA-64 ( https://en.wikipedia.org/wiki/IA-64#Architecture ) already exists, with its explicitly parallel instruction set, which leaves branch prediction and speculative execution up to the software. So you can still get many of the performance benefits, but it's under control of the software, giving a lot more flexibility for being able to mitigate or eliminate these kinds of issues. I thin…

I think this is overlooking how unpopular IA64 was. "Leaves branch prediction and speculative execution up to the software" means that in practice you need to either use the Intel compilers or hand-optimise your software to get the benefits, while simply recompiling your legacy software with GCC or LLVM ends up being disappointingly slow.

One big problem was the epic power consumption of the Itanic CPUs.

I remember going to a corporate presentation by Intel about the revolutionary CPU architecture. They had to turn the machine off because the cooling fan was making so much noise we couldn't hear the speaker.

And this at precisely the wrong moment in history, as mobile devices, with their stringent power consumption constraints, were becoming popular.

Re: Is it time for open processors?

#202

Post by freedomben » Sat, Jan 20, 2018, 3:55 AM UTC

dspillett wrote: post #54

B-Con wrote: post #34

The problem is less about openness itself and more about quality of auditing. Open isn't a magic bullet. As I understand, these latest CPU vulnerabilities were in the spec themselves. You could've found them by reading the manual. See what good that did us. But I posit that open projects do better with audits than closed because they are more likely to have open audits as well, and an open audit is harder to ignore o…

> Open isn't a magic bullet. > more about quality of auditing. Exactly. Being open makes things easier to audit, and to an extent encourages better due diligence (as embarrassments due to silly mistakes or, worse, attempted cover-ups, are more public!), but it doesn't enforce this in any way nor does it guarantee quality or completeness.

Fortunately as we saw from the OpenSSL debacle a while back, often deep corporate pockets (like Google) will step up and audit/patch these projects. Being open is obviously a pre-requisite for that to happen.

Re: Is it time for open processors?

#203

Post by BaronVonSteuben » Sat, Jan 20, 2018, 3:57 AM UTC

simias wrote: post #72

B-Con wrote: post #34

The problem is less about openness itself and more about quality of auditing. Open isn't a magic bullet. As I understand, these latest CPU vulnerabilities were in the spec themselves. You could've found them by reading the manual. See what good that did us. But I posit that open projects do better with audits than closed because they are more likely to have open audits as well, and an open audit is harder to ignore o…

I'd pay good money for an open and simpler platform to run my security-critical tasks that don't require top performance. Auditing a modern high-end CPU is probably a huge task even if you have access to the HDL because of how complex they are. A simpler design (RISC, no out-of-order execution, basic branch prediction and prefetching...) ought to be fast enough with modern lithography to browse the web, send emails a…

I think this is the first time I've heard advocated that a government should be in the business of chip design. We're a long way from the days of John Locke and enlightenment liberalism.

Re: Is it time for open processors?

#204

Post by freedomben » Sat, Jan 20, 2018, 4:02 AM UTC

ken wrote: post #167

B-Con wrote: post #34

The problem is less about openness itself and more about quality of auditing. Open isn't a magic bullet. As I understand, these latest CPU vulnerabilities were in the spec themselves. You could've found them by reading the manual. See what good that did us. But I posit that open projects do better with audits than closed because they are more likely to have open audits as well, and an open audit is harder to ignore o…

I think there's a huge difference between "take an existing system design, and declare it open" and "design a system in the open". This article isn't suggesting Intel make x86 open to all, for example. You get a completely different design when something is designed behind closed doors as a black-box product, versus designed in the open. Linux and Windows have drastically different designs, based on how they grew up.…

Is this the StarOffice you were referring to? https://en.wikipedia.org/wiki/StarOffice

Is that still being hacked on? I thought most of the OO people moved to Libre Office

Re: Is it time for open processors?

#205

Post by freedomben » Sat, Jan 20, 2018, 4:04 AM UTC

RandomCSGeek wrote: post #131

nerdponx wrote: post #113

Earlier quoted context omitted.

As I understand it, according to an article that was posted here a day or two ago, Meltdown was in fact discovered by a young Google engineer poring over the x86 manual.

Yes. A 22 y/o guy.

That's incredible. It makes me feel like I haven't done anything with my life :-D

Re: Is it time for open processors?

#206

Post by bogomipz » Sat, Jan 20, 2018, 5:31 AM UTC

hajile wrote: post #151

lambda wrote: post #106

Earlier quoted context omitted.

Why give up on performance? IA-64 ( https://en.wikipedia.org/wiki/IA-64#Architecture ) already exists, with its explicitly parallel instruction set, which leaves branch prediction and speculative execution up to the software. So you can still get many of the performance benefits, but it's under control of the software, giving a lot more flexibility for being able to mitigate or eliminate these kinds of issues. I thin…

IA-64 was a dumpster fire. The halting problem is unsolvable. You can't schedule branch prediction absolutely. You have to have information about the current running program. Branch prediction, instruction re-ordering, and speculative execution are to hardware what a JIT is to software (roughly speaking). Unfortunately, from a security perspective, moving those things to software doesn't make the vulnerability go awa…

>"The halting problem is unsolvable"

Can you elaborate on how the halting problem relates to the IA-64 architecture?

Re: Is it time for open processors?

#207

Post by duncan_bayne » Sat, Jan 20, 2018, 5:41 AM UTC

StreamBright wrote: post #156

pjmlp wrote: post #64

Earlier quoted context omitted.

I am yet to see any open source project subjected to the same high quality workflows as commercial propriety software targeted for high integrity computing deployment. Could you provide an example?

I am not sure when this mantra will stop that open source is safer when we know that it isn't.

That's not what I said; please stop putting words in my mouth.

Also, I hope you're not posting that from an Intel machine ;)

Re: Is it time for open processors?

#208

Post by nbsd4lyfe » Sat, Jan 20, 2018, 7:15 AM UTC

deepnotderp wrote: post #166

lambda wrote: post #106

Earlier quoted context omitted.

Why give up on performance? IA-64 ( https://en.wikipedia.org/wiki/IA-64#Architecture ) already exists, with its explicitly parallel instruction set, which leaves branch prediction and speculative execution up to the software. So you can still get many of the performance benefits, but it's under control of the software, giving a lot more flexibility for being able to mitigate or eliminate these kinds of issues. I thin…

You're giving up on a ton of performance by dropping OoOE. In particular, you end up losing the ability to avoid stalling on cache misses, and the memory wall becomes an increasingly gigantic problem even as Moore's Law progresses.

I don't think you necessarily have to miss it on a threaded CPU, but that isn't as optimal.

Re: Is it time for open processors?

#209

Post by totemizer » Sat, Jan 20, 2018, 7:39 AM UTC

B-Con wrote: post #34

The problem is less about openness itself and more about quality of auditing. Open isn't a magic bullet. As I understand, these latest CPU vulnerabilities were in the spec themselves. You could've found them by reading the manual. See what good that did us. But I posit that open projects do better with audits than closed because they are more likely to have open audits as well, and an open audit is harder to ignore o…

"open isn't a magic bullet" yeah, but closed is a harmful pattern. Open isn't about everything magically getting better, but when you do close development of something that potentially influences billions of people, it's an invitation for disaster. We do not want open because we like open, we want open because we are afraid of closed.

and just to be clear, the least whatever you are doing in a closed format affects people the least i want it to be open.

Re: Is it time for open processors?

#210

Post by ladberg » Sat, Jan 20, 2018, 7:54 AM UTC

gravypod wrote: post #200

I'm interested in the possibility of eventually having FPGA-driven systems where you can load up an ISA and use that. Imagine if every week you could expect an ISA architecture update that came with a power usage or speed improvement.

The problem is that no FPGA-driven system will come close to beating out a modern CPU, so people will have very little incentive to actually use it because it will probably be more expensive and definitely slower.